Lotus Evora. Instruction - part 82

 

 

Lotus Service Notes   

 

 

    Section PN

Re-circulation Pump

A coolant re-circulation electric pump is mounted beneath the air cleaner, and is plumbed into the heater 

supply line.  When energised, the pump circulates coolant through the heater system, drawing coolant from the 

back of the cylinder head, and pumping it through the heater matrix and back to the engine.

Heat Soak

After ignition switch off, the ECU remains live for a minimum period of 1 minute for coolant temperatures 

below 75°C (at time of switch off), extending progressively to a maximum period of 10 minutes for temperatures 

over 90°C.  If, during this period, the coolant temperature exceeds 110°C, the re-circ. pump will be activated 

and will run for a maximum period of 6 minutes, or until the coolant temperature falls to 50°C.

If, during the ECU live period the coolant temperature rises to 120°C, the cooling fans will run at slow speed 

in addition to the re-circ. pump, for a maximum period of 2 minutes, or until the temperature falls to 70°C.

PN.4 - REFRIGERANT HANDLING

The system is charged with 0.625 kg of refrigerant HFC R134a, and the following precautions MUST 

ALWAYS BE OBSERVED.

1.  On no account should refrigerant ever be discharged to atmosphere - use a refrigerant recovery/recycling 

station in accordance with the manufacturer's instructions.  

2.  Standard R134a 'quick fit' connectors are provided in the compressor suction and discharge pipes at the 

right hand front of the engine bay;

 

- the low pressure vapour line port is fitted in the pipe between the evaporator and compressor.

 

- the high pressure liquid line port is fitted in the pipe between the compressor and condenser.

3.  Heavy concentrations of refrigerant vapour can produce toxic gas if exposed to a naked flame.  The gas 

can also attack metal.

4.  Refrigerant drums must never be left open - always ensure the caps are securely fitted.

5.  Never transport drums of refrigerant in the passenger compartment of a car.

6.  Never expose refrigerant drums to high temperature.

7.  Never weld or use a steam cleaner in close proximity to any part of the air conditioning system.

8.  Never expose the eyes to vapourised or liquid refrigerant -   ALWAYS wear safety goggles and gloves when 

handling refrigerant.

PN.5 - REFRIGERANT PIPEWORK PRECAUTIONS

The following precautions must be observed when carrying out any work on the refrigerant pipework: 

Before disconnecting any refrigerant pipework, the refrigerant must first be recovered using suitable equipment 

connected to the service valves located at the rear of the right hand front wheelarch, behind the wheelarch liner.

Ensure that the equipment is suitable for R134a.

1.  All replacement components and flexible end connections are sealed when new, and should only be 

opened IMMEDIATELY PRIOR TO FITTING, AND AT ROOM TEMPERATURE, to prevent condensation 

of any moisture which may enter when the sealing is removed.

2.  Pipes, flexible end connections and components, must be capped immediately they are opened to prevent 

the ingress of moisture and/or dirt.

3.  The receiver-drier should be the LAST component to be connected, to ensure optimum dehydration and 

maximum moisture protection of the system.

 

 

Lotus Service Notes   

 

 

    Section PN

Key

Description

Qty

Thread

Pitch

Torque

1

Compressor to engine

4

M8

25 Nm

2

A.C. hoses to compressor

2

M6

9 Nm

3

Sill pipe to comp. hose, high pressure

1

3/4 - 16 UNF

1.6

25-30 Nm

4

Sill pipe to comp. hose, low pressure

1

1 1/16 - 14 UNS

1.8

35-40 Nm

5

Sill pipe to condenser pipe 

1

3/4 - 16 UNF

1.6

25-30 Nm

6

Receiver-drier connections

2

5/8 - 18 UNF

1.4

25-30 Nm

7

Evaporator pipe to receiver-drier

1

5/8 - 18 UNF

1.4

20-25 Nm

8

Trinary switch to pipe

1

3/8 - 24 UNF

10-13 Nm

9

Clamp plate, pipes to cond & exp valve 

1

M6

1.0

9 Nm

10

Clamp plate, expansion valve to evap

1

M5

0.8

6 Nm

11

Evaporator to sill pipe

1

1 1/16 - 14 UNS

1.8

35-40 Nm

# Use refrigeration oil only, smear on “O” rings and threads prior to assembly

(Gloves should be worn when handling refrigeration oil - see data sheet)

Key

Description

Diameter

Part Number 

A Suction line to compressor.  Condenser connections

16 mm

A120P6002H

B High pressure line to compressor

13 mm

A120P6001H

C Suction pipe to sill pipe and expansion valve

19 mm

A082P6081F

D High pressure line to sill pipe

12 mm

A082P6079F

E Receiver-drier connections and expansion valve inlet 

9 mm

A082P6078F

Refrigerant Pipework Fixing Torques

Refrigerant Pipework 'O' Rings

                A                E6                                  

p115

        9

                                      C11

                                       

                        E          C       D5

                               

                     10            9                             D3   C4

                 

                  E              C 

                                                  B1

                                         

                                                  A2

 

 

Lotus Service Notes   

 

 

    Section PN

4.  All joints should be coated with refrigeration oil before making any connections, to aid seating.

5.  Great care must be taken to prevent damage to the pipe fittings and connections, since due to the high 

pressures involved, a leak can be caused by the slightest imperfection.  Always use two spanners of the 

correct size when releasing or tightening any pipe joint so that the fixed part of the union may be prevented 

from twisting and damaging the component.  This is especially important with the aluminium condenser.

6.  All pipes and hoses must be free from any kinking.  The efficiency of the system can be impaired by a 

single kink, or restriction.  Flexible hoses should not be bent to a radius which is less than ten times the 

diameter of the hose.

PN.6 - REFRIGERANT OIL

The internal working parts of the compressor are lubricated by refrigerant oil.  This is a special type of oil 

which has an affinity with the refrigerant, such that a proportion of the oil circulates with the refrigerant, around 

the whole system.  Under normal operating conditions, the oil never needs changing or replenishing, and if 

the correct procedure for system depressurisation and re-charging is followed, minimal oil will be lost from the 

system during these operations.  If, however, the system suffers a major leak or sudden de-pressurisation, most 

of the oil held in suspension will be lost as the refrigerant escapes, necessitating the addition of a specified 

quantity of oil to the compressor on re-assembly (see section PN.7).  

If a refrigeration component is to be replaced, the removed item will contain a certain amount of oil, and 

a corresponding amount of new oil must be added to the system on re-assembly:

Condenser;            30 cm³

Evaporator;            30 cm³

Any major pipe or hose;    10 cm³

Receiver-drier;          30 cm³

Approved Oils

Use only Denso ND-OIL 8 low viscosity (ISO46) PAG oil or equivalent (Sanden SP10; Four Seasons 59007). 

 

Refrigerant oil absorbs water and should not be exposed to the atmosphere for any longer than is strictly 

necessary to perform the operation.  Never return decanted oil back into the storage container.

PN.7 - COMPRESSOR

The a.c. compressor is mounted at the left hand front of the crankcase, and is driven from the crankshaft, 

together with the alternator, PAS pump and water pump, by a multi-rib, serpentine, synthetic belt.  A maintenance 

free belt tensioner takes the form of an idler pulley mounted on a sprung eccentric hub, which mechanism 

applies pressure to the smooth, back side of the belt between the crankshaft and water pump, and provides a 

generous belt wrap around the crankshaft pulley.

The belt itself should be inspected for condition at each service interval, and if it exhibits any evidence of 

physical damage, cracking, fraying, perishing, abrasion, contamination or any other deterioration, it should be 

replaced.  In the case of oil or coolant contamination, the cause must be identified and rectified, and each of 

the pulleys must be thoroughly degreased before the new belt is fitted.

Compressor Removal

1.  Remove the RHF wheelarch liner and recover the refrigerant using equipment connected to the service 

ports at the rear of the wheelarch.

2.  Remove the driver's seat and cabin rear bulkhead trim.  Remove the bulkhead access panel.

 

3.  Remove the RHR wheel and wheelarch liner.  Using a hexagonal 14mm socket applied to the auxiliary 

belt tensioner bolt, relieve the tension on the auxiliary drive belt by turning counterclockwise, and insert a 

5 mm locking pin in the hole provided in the tensioner hub.

 

 

Lotus Service Notes   

 

 

    Section PN

4.  Release the clamp plate securing each of the pipes to the compressor and immediately cap the pipes and 

compressor ports to prevent ingress of dirt and moisture.  Secure the two pipe/hoses aside.

5.  Disconnect the two compressor electrical harness plugs.

6 

Remove the four bolts securing the compressor to the engine, disengage the drive belt and withdraw the 

unit through the bulkhead aperture.  Retain the compressor for oil quantity measurement if a new unit is 

to be fitted. 

 

Oil Quantity Adjustment Prior to Compressor Refitment

Refitting Existing Compressor

i) 

If the existing compressor is to be refitted after normal refrigerant recovery has been performed, a quantity 

of oil equivalent to that recovered must be added to that already held in the compressor.  

ii)  If the system has suffered a rapid discharge, caused for example by accident damage, most of the re-

frigerant oil will have been lost.  Drain the remaining oil from the compressor by removing the drain plug 

and rotating the clutch plate.  Add 150 cm³ of new refrigerant oil (see above) to the compressor before 

refitment.

Fitting New Compressor

 

New compressors are sealed and pressurised with nitrogen gas.  The sealing caps should be removed 

only immediately prior to compressor fitment, at which time the gas pressure should be heard to escape 

as a cap is slowly released.  New compressors are supplied with an oil fill of 150 cm³.

iii)  If normal refrigerant recovery has been performed, the new compressor oil should be drained off, and the 

required oil quantity in the new compressor calculated and added:

 

- Drain and measure the oil quantity in the OLD compressor by removing the drain plug and rotating the 

clutch plate. Quantity = X cm³

 

- Oil quantity to be added to new compressor = X + 10 cm³

iv)  If the system has suffered a rapid discharge, caused for example by accident damage, most of the refriger-

ant oil will have been lost.  In this case, fit the new compressor as supplied with its 150 cm³ oil charge.

Illustration TBA